In return, the Marlins will get second baseman Emilio Bonifacio and two low-level prospects. The Marlins did not immediately confirm the report, but Olsen and Willingham were informed of the deal. A baseball official with knowledge of the trade said it was done.

"I didn't think I was going to get traded, to be honest with you," said Willingham, who along with Olsen will be introduced at a news conference today in Washington. "I also knew there was a good possibility I was going to get traded because they weren't going to be able to sign all the arbitration-eligible guys."

President of baseball operations Larry Beinfest was at Monday's Heat game. Approached by several media members, Beinfest said he was aware of the report, but neither confirmed nor denied it.

Until Monday, Olsen and Willingham had spent their entire careers with the Marlins. Willingham was a 17th-round draft pick in 2000, and Olsen arrived as a sixth-rounder two years later.

"It's the only organization I've known, but I also understand," Willingham said. "You have to look at it a couple of ways. The positive of it is it's a new opportunity ... I've developed a lot of good relationships, and I'm going to miss those guys. ... I love the Marlins."

Bonifacio's arrival does not signal second baseman Dan Uggla's departure. Though Bonifacio entered last season as the sixth overall prospect in the Diamondbacks' system, according to Baseball America, he isn't a lock to break camp with the Marlins.

The slick-fielding, blazing-fast Bonifacio appeared in eight games for the Diamondbacks last season before they traded him to the Nationals for reliever Jon Rauch. Bonifacio, 23, hit .248 with a .305 on-base percentage in 41 games with his new team. A natural middle infielder, the Marlins might experiment with Bonifacio at third.

The Marlins also acquired right-hander P.J. Dean, 20, a seventh-round pick out of New Caney (Texas) High School in 2007. Last season with Vermont of the Class A short-season New York-Penn League, he went 4-1 with a 1.57 ERA, 16 walks and 34 strikeouts in 10 starts (46 innings).

Jake Smolinski, an ultra-athletic infielder/outfielder out of Rockford, Ill., also is headed to the Marlins. A second-round pick in 2007, Smolinski was set to attend Clemson, but the Nationals lured him with a $452,500 signing bonus.

Smolinski, 19, split last season between the Gulf Coast League, Vermont and low-Class A Hagerstown, batting a combined .271 with four homers and 33 RBI in 77 games. He mostly played second base.

Staff Writer Ira Winderman contributed to this report. Juan C. Rodriguez can be reached at jcrodriguez@SunSentinel.com